proxy: add more columns to parquet upload (#6405)

## Problem

Some fields were missed in the initial spec.

## Summary of changes

Adds a success boolean (defaults to false unless specifically marked as
successful).
Adds a duration_us integer that tracks how many microseconds were taken
from session start through to request completion.

proxy/src/context.rs

@@ -32,6 +32,7 @@ pub struct RequestMonitoring {
     user: Option<SmolStr>,
     application: Option<SmolStr>,
     error_kind: Option<ErrorKind>,
+    success: bool,
 
     // extra
     // This sender is here to keep the request monitoring channel open while requests are taking place.
@@ -59,6 +60,7 @@ impl RequestMonitoring {
             user: None,
             application: None,
             error_kind: None,
+            success: false,
 
             sender: LOG_CHAN.get().and_then(|tx| tx.upgrade()),
             latency_timer: LatencyTimer::new(protocol),
@@ -96,6 +98,10 @@ impl RequestMonitoring {
         self.user = Some(user);
     }
 
+    pub fn set_success(&mut self) {
+        self.success = true;
+    }
+
     pub fn log(&mut self) {
         if let Some(tx) = self.sender.take() {
             let _: Result<(), _> = tx.send(self.clone());